The present invention relates generally to magnetic stripe card readers and more specifically to magnetic stripe card readers that encrypt information extracted from a magnetic stripe.
Documents bearing magnetic stripes, such as magnetic stripe cards, are commonly used in a variety of transactions. In many instances data read from the magnetic stripe can be provided to a server to verify that the document bearing the magnetic stripe is authentic.
A number of different approaches are known for authenticating a document bearing a magnetic stripe. One approach is to extract data stored on the magnetic stripe and verify the authenticity of the data. Another approach that can foil attempts to reproduce information recorded on a magnetic stripe is to extract data concerning the physical characteristics of the magnetic stripe itself. Observations of the materials used to construct magnetic stripes have revealed that each material is unique and generates magnetic field with unique characteristics that are observable. When a signal is generated that is indicative of the magnetic field, the component of the signal that is indicative of this unique characteristic is often referred to as the remanent noise signal of the material. A number of authentication processes compare information concerning the remanent noise signal of a magnetic stripe on the document presented with known information concerning the remanent noise characteristic of the magnetic stripe of the authentic document. Correlation between the information suggests that the document presented is in fact authentic. Processes that seek to extract information that is unique to a particular magnetic stripe or data recording on a magnetic stripe are commonly referred to as ‘Magnetic Fingerprinting’ techniques.